# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: The Bygrave
From: Hanno Ix
Date: 2009 Jul 31, 20:40 -0700
 True. That's why I am working on my own version of this, too.:)--- On Fri, 7/31/09, glapook@pacbell.net wrote:From: glapook@pacbell.net Subject: [NavList 9276] Re: The BygraveTo: "NavList" Date: Friday, July 31, 2009, 5:24 PMAnd, of course, making the flat version avoids this issue completely.glOn Aug 1, 1:23 am, "glap...@pacbell.net" wrote:> You make it too hard. It is simple to print out the scale and try it> on for size. Then you just adjust the printer commands to change the> size of the printed scales and try it on again. A few iterations like> this and you have a scale that fits on your cylinder.>> gl>> On Jul 26, 10:37 pm, Hanno Ix wrote:>> > Dear waldendand:>> > I have a technical question here:>> > When you designed this scale, what exactly was the diameter of the drum and the thickness of the paper? Did you perhaps make any experiments as to what paper length fits exactly around the drum after it has been bend to a cylinder?>> > I see things this way:>> > To fit precisely, the cylinder formed by the paper needs to have an inner diameter equal to the outside diameter of the drum. So, because of the thickness of the paper, the outside of the paper cylinder must be bigger yet. As you bent the paper it will be deformed somewhat, and  the cylinder's inside/outside diameters will probably be different from the original paper length divided by pi. Since the scale is printed on the outside  this would impact the accuracy of the scale. This error need not be big to cause errors of a min or more.>> > It seems difficult to predict the deformation of the paper, given the complexity of its matrix. So I wonder, Is there anyone that has observed such an effect in the practical world? If it was not negligible, how did you deal with it?>> > Similar questions apply, of course, to the next scale (cosine) and perhaps a third (cursor).>> > If I were to make just a single Bygrave, I'd just turn the drum and/or play with the scale plotting routine until things fit. However, if we are perhaps talking about making a number of Bygraves we would need a more predictable solution.>> > Regards>> > --- On Wed, 7/22/09, waldend...@YAHOO.COM wrote:>> > From: waldend...@YAHOO.COM > > Subject: [NavList 9186] Re: The Bygrave> > To: NavList@fer3.com> > Date: Wednesday, July 22, 2009, 7:15 PM>> > Here's a revised version of a Bygrave scale.  I use a FORTRAN program to write out postscript text. >>

--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To unsubscribe, email NavList-unsubscribe@fer3.com
-~----------~----~----~----~------~----~------~--~---

Browse Files

Drop Files

### Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

### Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

### Email Settings

 Posting Code:

### Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)